Archaeoseismology and Palaeoseismology in the Alpine ... - Tierra

1 st INQUA‐IGCP‐567 International Workshop on Earthquake Archaeology and Palaeoseismology
QUANTITATIVE METHODS IN ARCHAEOSEISMOLOGY
K.G. Hinzen (1), C. Fleischer (1), S. K. Reamer (1), S. Schreiber (1), S. Schütte (2) and B. Yerli (3)
(1) Earthquake Geology Group, Cologne University, Vinzenz‐Pallotti‐Str. 26, 51429 Bergisch Gladbach. GERMANY. hinzen@uni‐koeln.de
(2) Archaeological Zone Cologne, City of Cologne, Heumarkt 64‐66, 50667 Köln, GERMANY
(3) Institute Geology, Mineralogy and Geophysics, Ruhr‐Universität Bochum, Universitätsstraße 150, 44801 Bochum, GERMANY.
Abstract: Within the multidisciplinary field of archaeoseismology, quantitative methods have begun to be utilized more prevalently. We
propose a scheme of applying quantitative models to test the seismogenic hypothesis of observed damages. The combination of 3D structural
models of buildings or their remains based on phase shift laser scanner measurements with high resolution digital images allow the
construction of damage and/or deformation inventory and assists the archaeological work during an excavation. 3D surface meshes derived
from the same scan data are the basis for Finite or Discrete Element models of the structures. The effect of site‐specific earthquake‐related
ground motions, other natural causes, and anthropogenic influences, are simulated and compared with the damage inventory. However, due
to the high level of complexity of the problems no definite answers should be expected from quantitative models in all cases.
Key words: Quantitative Methods, archaeoseismology.
INTRODUCTION
The early approaches in the relatively young field of
archaeoseismology were qualitative, consisting mainly of
descriptions of observed damages in archaeological
excavations and were often highly speculative with
regards to the damage processes. Increasingly,
quantitative models have recently begun to be employed.
Galladini et al. (2006) summarized complete
archaeoseismic studies in a flow chart, emphasizing
quantitative models as crucial tools to validate or
eliminate a seismogenic hypothesis, which usually forms
the basis for an archaeoseismic investigation. In Fig. 1, we
propose a scheme that concentrates on archaeoseismic
problems in which off‐fault ground motions are the
suspected cause of damages to manmade structures. We
apply this scheme in two projects: the Archaeological
Zone Cologne, Germany and the ancient Lycian City of
Pinara, SW Turkey.
Conclude
Damage
Inventory
Compare
3D Scans,
Color Images
Orthophotos
Crosscuts
3D Meshes
Reconstruction
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LASER SCANNING
Advanced 3D laser scans combined with high‐resolution
digital photographs allow detailed damage analysis even
for cases where the stability of the excavated objects,
safety or the lack of time prevents a thorough classical
archaeological documentation. (An example will be given
in the accompanying paper of Schreiber et al., 2009).
Using the phase shift instead of travel time of the laser
beam allows very rapid data acquisition with several
million points per minute and results in a resolution of 1‐
2 mm in the 0.5 to 75 m distance range.
While we combine individual scans, perform signal‐
enhancing filtering and combination with color photos
with the Reconstructor software tool, standard CAD and
GIS tools are used to set up the damage inventory.
Parallel to this inventory and based on the same raw data,
orthophotos, crosscuts and 3D mesh surfaces are
constructed. In excavation‐parallel studies, as in the
above‐mentioned Cologne field case, the scanned images
DEM, Boreholes,
Samples, Geophysics
Geotechnical
Model
FE & FD Models of the
Damaged Stuctures
Dynamic Behaviour
Building Capacity
Ground Motion
Seismotectonic
Seismicity
Seismological
Model
Fig. 1: Schematic flow chart of quantitative archaeoseismic modelling.
Other Natural or
Man Made Effcts